The present invention relates generally to telecommunication techniques. More specifically, embodiments according to the present invention provide techniques for providing efficient and smooth communicational access for wireless devices. In particular, various embodiments according to the present invention are compatible with the mobile IPv6 standard. Merely by way of example, the invention has been applied to handover techniques for mobile devices. But it would be recognized that the invention has a much broader range of applicability.
In the past decade, communication technologies rapidly developed. Various communication mediums have been explored, ranging from power line, telephone line, optical line, to wireless communication. Most recently, wireless communication has become more and more popular and widely adopted for the convenience that it offers.
Wireless communication has many applications. Among other things, mobile phones that utilize wireless communication techniques are one of the most popular communicational devices, who claim billions of users today. Another popular application using wireless communication devices is mobile computing devices accessing local networks via wireless links. Through the local wireless networks, mobile computing devices are able to connect to the Internet using wireless internet protocol (IP) technology. Most recently, standard setting organizations such as the Internet Engineering Task Force (IETF) and Institute of Electrical and Electronics Engineers (IEEE) have developed and promoted various standards for wireless communication networks. For example, the IETF has developed a Mobile IP standard, which is a communications protocol that is designed to allow mobile device users to move from one network to another while maintaining a permanent IP address.
According to the Mobile IP standard, a mobile device can have two addresses: a permanent home address and a care of address (CoA). Typically, the permanent home address is associated with the home agent that mobile device is connected, and the CoA is associated with the network the mobile device is visiting. For example, a home agent stores information about mobile nodes whose permanent address is in the home agent's network.
To illustrate, a mobile device that needs to access an IP network uses the home address of the mobile device to send and/or receive packets. These packets are intercepted by the home agent, which uses a table and routes the packets to the mobile device's CoA with a new IP header. The new IP header is added to the packet so the original IP header is preserved. The packets are decapsulated and delivered to the mobile device at the end of the routing process, and the added IP header is removed.
When acting as a sender, the mobile device simply sends packets directly to the other communicating node through the access router.
In a typical Mobile IP protocol, various procedures and messages are defined. For example, an authenticated registration procedure is used so that a mobile device informs its home agent(s) of its care-of-address“(es). An extension to ICMP Router Discovery is employed to allow mobile devices to discover prospective home agents. The rules for routing packets to and from mobile nodes, including the specification of one mandatory routing mechanism and several optional routing mechanisms.
Of course, for the scheme described above to work, it is a prerequisite that mobile devices are able to move from the HA to a foreign network. Over the past, various conventional techniques have been developed in accordance with the Mobile IP protocol to allow mobile devices users to move from one network to another using handover processes. Unfortunately, these conventional techniques are often inadequate.
Therefore, improved methods and system for performing handover is desired.